Users Guide

Rebuilding Redundant Information
Does my controller support this feature? See Supported Features.
If you have a redundant virtual disk, you can reconstruct the contents of a failed physical disk onto a new disk or a hot spare. A rebuild can
take place during normal operation, but it degrades performance.
A global hot spare drive can be part of different RAID level Virtual drives rebuilding operation on SWRAID controllers.
Managing Virtual Disk Bad Block Management
Virtual disk bad blocks are bad blocks on one or more member physical disks. The read operation on the virtual disks having bad blocks
may fail.
Storage Management generates a critical alert (2387) to notify you of the bad blocks on the virtual disk.
Virtual disk bad blocks are discovered when the controller performs any operation that requires scanning the disk. Examples of operations
that may result in this alert are:
• Consistency check
• Rebuild
• Virtual disk format
• I/O
• Patrol Read
Recovering a physical disk bad block depends on the RAID level and state of the virtual disk. If a virtual disk is redundant, the controller can
recover a bad block on a physical disk. If a virtual disk is not redundant, then the physical disk bad block results in a virtual disk bad block.
Table 32. Sample Scenarios For Virtual Disk Bad Blocks
RAID Level Virtual Disk State Scenario Result
RAID 0 Degraded One bad block on a physical
disk.
The controller cannot
regenerate data from the peer
disks as there is no redundancy.
This results in a virtual disk bad
block.
RAID 5 Ready One bad block on a physical
disk.
The controller regenerates data
from the peer disks and sends a
Write to the bad block. The disk
then remaps the Logical Block
Addressing (LBA) to another
physical location. The problem is
resolved.
RAID 5 Degraded One bad block on a physical
disk.
The controller cannot
regenerate data from the peer
disks because one drive is
missing. This results in a virtual
disk bad block.
RAID 5 Ready One bad block on two physical
disks at the same location.
The controller cannot
regenerate data from the peer
disks. This results in a virtual
disk bad block.
RAID 6 Partially degraded (one failed/
missing physical disk)
One bad block on a physical
disk.
The controller regenerates data
from the peer disks and sends a
Write to the bad block. The disk
then remaps the LBA to another
physical location. The problem is
resolved.
RAID 6 Degraded (two failed/missing
physical disks)
One bad block on a physical
disk.
The controller cannot
regenerate data from the peer
Virtual Disks 111